Sunday, February 13, 2011

Parkinsonís Disease Linked to Pesticides Rotenone and Paraquat

Parkinson's disease has been positively associated with two groups of pesticides by the National Institute of Environmental Health Sciences researchers who found that people who used two specific varieties of pesticide were 2.5 times more likely to develop Parkinson's disease.

The pesticides, paraquat and rotenone, are illegal for home and garden use. Earlier research on animals linked paraquat to Parkinson's disease, so its use is restricted to application by licensed professionals. Rotenone is approved only for use in killing invasive fish species.

"Rotenone directly inhibits the function of the mitochondria, the structure responsible for making energy in the cell," according to study co-author Freya Kamel, a researcher at the National Institute of Environmental Health Sciences.

"Paraquat increases production of certain oxygen derivatives that may harm cellular structures. People who used these pesticides or others with a similar mechanism of action were more likely to develop Parkinson's disease."

The study examined 110 people with Parkinson's disease and 358 people who served as a control group from the Farming and Movement Evaluation (FAME) Study. In 110 PD cases and 358 controls, PD was associated with use of a group of pesticides that inhibit mitochondrial Complex I (OR 1.7, 95% CI 1.0, 2.8) including rotenone (OR 2.5, 95% CI 1.3, 4.7), and with use of a group of pesticides that cause oxidative stress (OR 2.0, 95% CI 1.2, 3.6) including paraquat (OR 2.5, 95% CI 1.4, 4.7).

FAME is part of a larger Agricultural Health Study looking at the health of approximately 90,000 licensed pesticide applicators and their spouses.

The study appears in the journal Environmental Health Perspectives published by the National Institute of Environmental Health Sciences

Incidentally, during the late 1970s, a controversial program sponsored by the US government sprayed paraquat on marijuana fields in Mexico. Since much of this marijuana was subsequently smoked by Americans, the US government's "Paraquat Pot" program stirred much debate. Perhaps in an attempt to deter people from using marijuana, representatives of the program warned that spraying rendered the crop unsafe to smoke.

However, independent bodies have studied paraquat in this use. Jenny Pronczuk de Garbino, stated: "no lung or other injury in marijuana users has ever been attributed to paraquat contamination". Also a United States Environmental Protection Agency manual states: "... toxic effects caused by this mechanism have been either very rare or nonexistent. Most paraquat that contaminates marijuana is pyrolyzed during smoking to dipyridyl, which is a product of combustion of the leaf material itself (including marijuana) and presents little toxic hazard.Ē